Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Antimicrob Agents Chemother ; 56(3): 1458-65, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22183171

RESUMO

Hospital-acquired infections caused by drug-resistant bacteria are a significant challenge to patient safety. Numerous clinical isolates resistant to almost all commercially available antibiotics have emerged. Thus, novel antimicrobial agents, specifically those for multidrug-resistant Gram-negative bacteria, are urgently needed. In the current study, we report the isolation, structure elucidation, and preliminary biological characterization of a new cationic lipopeptide antibiotic, battacin or octapeptin B5, produced from a Paenibacillus tianmuensis soil isolate. Battacin kills bacteria in vitro and has potent activity against Gram-negative bacteria, including multidrug-resistant and extremely drug-resistant clinical isolates. Hospital strains of Escherichia coli and Pseudomonas aeruginosa are the pathogens most sensitive to battacin, with MICs of 2 to 4 µg/ml. The ability of battacin to disrupt the outer membrane of Gram-negative bacteria is comparable to that of polymyxin B, the last-line therapy for infections caused by antibiotic-resistant Gram-negative bacteria. However, the capacity of battacin to permeate bacterial plasma membranes is less extensive than that of polymyxin B. The bactericidal kinetics of battacin correlate with the depolarization of the cell membrane, suggesting that battacin kills bacteria by disrupting the cytoplasmic membrane. Other studies indicate that battacin is less acutely toxic than polymyxin B and has potent in vivo biological activity against E. coli. Based on the findings of the current study, battacin may be considered a potential therapeutic agent for the treatment of infections caused by antibiotic-resistant Gram-negative bacteria.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Escherichia coli/efeitos dos fármacos , Lipopeptídeos/farmacologia , Paenibacillus/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Antibacterianos/biossíntese , Antibacterianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Transporte Biológico/efeitos dos fármacos , Permeabilidade da Membrana Celular , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/crescimento & desenvolvimento , Fermentação , Células HEK293 , Hemólise , Humanos , Cinética , Dose Letal Mediana , Lipopeptídeos/biossíntese , Lipopeptídeos/isolamento & purificação , Camundongos , Testes de Sensibilidade Microbiana , Polimixina B/farmacologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Espectrometria de Massas em Tandem
2.
J Antibiot (Tokyo) ; 66(4): 219-23, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23232928

RESUMO

Two new polyketides, 6,8,5'6'-tetrahydroxy-3'-methylflavone (1) and paecilin C (2), together with six known analogs secalonic acid D (3), secalonic acid B (4) penicillixanthone A (5), emodin (6), citreorosein (7) and isorhodoptilometrin (8) were obtained from a broth of gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023. Compounds 1 and 6-8 had significant antifouling activity against Balanus amphitrite larvae settlement with EC50 values of 6.7, 6.1, 17.9 and 13.7 µg ml(-1), respectively, and 3-5 showed medium antibacterial activity against four tested bacterial strains. This was the first report of antibacterial activity of 3-5 against marine bacteria and antifouling activity of 6-8 against marine biofouling organism's larvae. The results indicated that gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023 strain could produce antifouling and antibacterial compounds that might aid the host gorgonian coral in protection against marine pathogen bacteria, biofouling organisms and other intruders.


Assuntos
Antozoários/microbiologia , Antibacterianos/biossíntese , Penicillium/metabolismo , Policetídeos/metabolismo , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Flavonas/isolamento & purificação , Flavonas/farmacologia , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Praguicidas/isolamento & purificação , Praguicidas/farmacologia , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Thoracica/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA